The overwhelming majority of childcare worldwide is provided by parents. In many cultural contexts worldwide, childcare is a family endeavor: when parents must work, children may be cared for by extended family members or other close relatives and friends within a formal or informal kinship network. In many industrialized nations, the economic necessity of two-parent income and the increasing isolation of the nuclear family creates a necessity for external, professional childcare. In the United States, for example, parents and guardians may choose between in-home childcare, such as a nanny or babysitter, or formal childcare in either a home or center-based care setting. The latter are often subject to licensure and review by the state, whereas the former is much more informal. The National Network for ...